What is the concentration of Htions at a pH = 7?
mol/L
What is the concentration of OH-ions at a pH = 7?
mol/L
What is the ratio of H+ ions to OH-ions at a pH = 7?

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation:

i would say b

explanation:

but i think i would need more information than that

answerto predict;